Phakic IOLs, striving for improvement, still a viable option for selected patients

Brought to the market in the late 1980s, phakic IOLs promised to be the solution for patients with high refractive error who were not eligible for corneal laser surgery. The initial enthusiasm cooled down in the following years due to long-term sight-threatening complications that induced companies to repeatedly modify some of the existing IOL designs and eventually withdraw several models from the market.

Although the use of phakic IOLs did not expand as much as was expected at first, this technology still has a role in patients who are not eligible for corneal refractive surgery.

“It may be because the cornea is too thin, the myopia is too high, or the cornea presents abnormalities,” Mohamad Rosman, MD, said. “However, we must be aware of the risks, which can be significant and even lead to blindness.”

Image: Rosman, M

Asian eyes have shallower anterior chambers and smaller angle-to-angle width compared with Caucasian eyes, as reported by several studies. This might affect the choice and sizing of the lens or be a contraindication in some cases even if myopia is very high.

“Phakic IOLs are a small percentage of my refractive procedures, around 5%. They are a niche procedure to offer only in case corneal refractive surgery is not indicated,” Rosman said.

Posterior chamber ICL

Two models of phakic IOLs have stood the test of time: the posterior chamber ICL (STAAR Surgical) and the anterior chamber iris-claw Artisan/Artiflex (Ophtec).

According to the Global Strategic Business Report 2015-2020, the Visian ICL currently dominates the global phakic IOL market.

“I implanted the ICL 15 years ago and then stopped because of the high incidence of cataract. I came back to this technology when the central hole, the Aquaport, was introduced, and now I am very happy,” Antonio Marinho, MD, OSN Europe Edition Board Member, said.

The central hole, 360 µm in diameter, allows a more natural flow of the aqueous between the IOL and the crystalline lens, and helps to prevent IOP increase and cataract formation.

“I used to do peripheral iridotomies, and now, with the hole in the lens, this is no longer necessary. However, there is a chance that the hole gets blocked by viscoelastic remnants trapped behind the lens,” Rosman said.

For this reason, he recommended monitoring IOP carefully in the first hours after surgery, at day 1 and in the following week.

The ICL is the best phakic IOL for Asian eyes because it lays farther away from the cornea, he said. He also likes it because of the small incision and the possibility to correct astigmatism at the same time using the toric model.

Sizing, patient selection and surgery

A problem with the ICL is the sizing, which is not well established and still relies on white-to-white measurement.

“It may correspond to the sulcus-to-sulcus in about 85% of the cases, but there is still 15% where it does not,” Marinho said.

If the lens is too big, the high vault may cause IOP rise and glaucoma. If the size is too small and the vault too low, the lens might come into contact with the crystalline lens, leading to cataract formation.

“The nomogram for ICL sizing is based on the Caucasian population and may not be as accurate for Asian eyes,” Rosman said.

Successful ICL implantation starts with inclusion criteria related to anterior chamber depth and configuration of the iris and angle.

“Even if you think that the ICL is far from the endothelium and that the anterior chamber does not matter, it matters, and eye anatomy and configuration should be carefully studied with the OCT,” Marinho said.

“The first thing to do is measure the white-to-white carefully, preferably using an Orbscan (Bausch + Lomb). I also use UBM to measure the sulcus-to-sulcus and compare the readings,” Rosman said.

He recommended choosing patients wisely because a shallow chamber makes surgery difficult and is a high risk factor with this lens postoperatively.

“Do not compromise on anterior chamber depth,” he said.

When doing surgery, he suggested taking into account that younger people tend to be more anxious. If in doubt, it is better to block the eye with anesthesia or even use general anesthesia.

“Observe and assess patients carefully during the visit and ask yourself if they are going to be cooperative under the microscope,” he said.

Surgery should be as gentle and precise as possible to avoid traumatizing the lens and the angle.

“Remember that this surgery is different from cataract surgery. The injection of the ICL needs to be very slow to allow the lens to unfold slowly and not turn upside down,” Marinho said.

Iris-claw Artisan/Artiflex

Camille Budo, MD, an OSN Europe Edition Board Member, started implanting the Artisan lens in 1988, went on to the foldable Artiflex and has performed approximately 5,300 iris-claw implantations.

“What I like about this lens is that it is a 100% surgeon-dependent lens. The surgeon is responsible for the indications, for the preoperative examinations, for the surgery, for the centration of the lens, the enclavation and quantity of iris tissue, and for the postoperative assessment. There are no surprises following successful surgery,” he said.

He recommended attending the Artisan/Artiflex training courses before approaching this surgery alone. Careful preoperative examination, including anterior chamber OCT imaging, should establish whether there is sufficient anterior chamber depth and a preoperative crystalline lens rise less than 600 µm. It is mandatory to exclude patients who do not perfectly fit the surgery profile.

“During surgery, only use appropriate instrumentation and a cohesive OVD, washing it out carefully at the end of the procedure. Before or during surgery, perform peripheral iridotomy. It is a safety belt for us to prevent postoperative Urrets-Zavalia syndrome,” he said.

Close monitoring after implantation is mandatory. Budo continues to see his patients who were implanted long ago once a year for an endothelial cell count and to evaluate the progression of crystalline lens rise.

The good news coming from Ophtec is that sales of the Artisan/Artiflex toric are steadily going up, according to Budo.

“I believe that the range of opportunities for phakic IOLs is increasing, as the limitations of laser become obvious. More patients are looking now for a reversible procedure, and multiple long-term results with the Artisan/Artiflex have shown they are a safe and effective technology,” he said.

Having learned from experience and having new means for measuring the eye, such as OCT scans, surgeons can now rely on more precise criteria for patient selection. Indications for phakic IOLs have narrowed and results are better, Budo said.

Angle-supported lenses

Marinho implanted angle-supported IOLs until 2014, when Alcon voluntarily withdrew the Cachet implant from the market due to concerns about abnormally high endothelial cell loss in some patients.

“My experience with the Cachet was very good. I implanted about 112 patients and only explanted three because of dislocation of the lens, not because of endothelial problems. My follow-up is about 7 years, and in all my cases the lens works well. I am following these patients very closely, and if I will ever see that there are signs of endothelial cell loss, I will explant the lens and do a lensectomy if they are older or lens exchange with an ICL if they are younger,” he said.

The reason why late complications occurred is still unclear.

According to Marinho, the protocol for the Cachet included patients with shallow anterior chambers, and this was the mistake that led to complications.

Both Marinho and Budo agreed that there is no future for the angle-supported concept.

“Already in the late ’90s some of us thought that angle-supported would be the disaster of the 21st century,” Budo said.

Newcomer

A novel posterior chamber phakic IOL, the Implantable Phakic Contact lens (IPCL), was recently developed by the Indian company Care Group and is commonly used in India. It is a single-piece posterior chamber phakic lens that can be injected into the eye through a sub-2.8-mm incision. It is customized according to the shape and size of the patient’s eye and has a wide power range, from +10 D to –25 D, with cylinder up to 8 D. The material is acrylic, 100% vegetarian, with no porcine collagen.

“Specific advantages of IPCL are the small incision size and the ability to correct high refractive error, customizing power in all possible combinations and providing crystal clear vision,” Suresh K. Pandey, MD, said.

It is also an iris-friendly lens, he said, because the edges are round. The six-pad haptics provide balance and stability.

Aqueous circulation is enhanced by a total opening area of 2,400 µm made up of six holes on the optic and optic-haptic vault.

“This prevents light scattering and allows equalizing of the pressure between the posterior and anterior chamber all across the lens,” Pandey said.

“I have implanted 120 patients with the IPCL since early 2013 and have performed the world’s first toric IPCL implantation in the same year and also demonstrated for the first time during the live surgery session in Pune, India. This is now the implant of choice in our practice,” Pandey said.

Another interesting feature of this lens is that it is available with a presbyopic optic based on a patented diffractive technique. The near add ranges between +1.5 D and +3.5 D to cater to the maximum number of presbyopic patients.

“We select cases who are motivated for minimizing their dependency on glasses and do not have any associated ocular diseases. A presbyopic toric variant is also available,” Pandey said.

Results with the presbyopic lens are excellent, and the majority of patients are satisfied with the outcome. The drawbacks are minimal, and patients are counseled before surgery about possible glare and halos. The patented refractive-diffractive optic profile ensures minimal optical disturbances, Pandey said.

The IPCL has become a popular implant in India. The cost of an IPCL is 17,000 rupees ($255), the toric model is 26,000 rupees ($400), and the presbyopic model costs 35,000 rupees ($526). – by Michela Cimberle

References:

Alió JL, et al. J Refract Surg. 2015;doi:10.3928/1081597X-20141202-01.

Alió JL, et al. JAMA Ophthalmol. 2013;doi:10.1001/jamaophthalmol.2013.5595.

Baïkoff G, et al. J Cataract Refract Surg. 2005;doi:10.1016/j.jcrs.2004.09.034.

Barsam A, et al. Cochrane Database Syst Rev. 2014;doi:10.1002/14651858.CD007679.pub4.

Budo C. J Cataract Refract Surg. 2010;doi:10.1016/j.jcrs.2010.07.008.

Doors M, et al. Am J Ophthalmol. 2012;doi:10.1016/j.ajo.2012.04.006.

Guber I, et al. JAMA Ophthalmol. 2016;doi:10.1001/jamaophthalmol.2016.0078.

Kohnen T, et al. J Cataract Refract Surg. 2010;doi:10.1016/j.jcrs.2010.10.007.

Leung CK, et al. Br J Ophth. 2010;doi:10.1136/bjo.2009.167296.

Morral M, et al. J Cataract Refract Surg. 2016;doi:10.1016/j.jcrs.2015.08.018.

Ostovic M, et al. J Cataract Refract Surg. 2013;doi:10.1016/j.jcrs.2013.02.005.

Pearls for toric Implantable Phakic Contact Lens by Dr Vidushi and Suresh Pandey. https://www.youtube.com/watch?v=La7m9mjoLpY.

Qin B, et al. Ophth Surg Lasers Imaging. 2012;doi:10.3928/15428877-20120102-03.

Shimizu K, et al. Medicine (Baltimore). 2016;doi:10.1097/MD.0000000000003270.

Wang D, et al. Clin Exp Ophth. 2012;doi:10.1111/j.1442-9071.2011.02746.

For more information:

Camille Budo, MD, is emeritus associate professor of ophthalmology at the University of Maastricht, The Netherlands. He can be reached at Hasseltsesteenweg 40-B 3800 Sint-Truiden, Belgium; email: camille.budo@gmail.com.

Antonio Marinho, MD, PhD, is chairman of the Department of Ophthalmology, Hospital Arrábida, Porto, Portugal. He can be reached at email: marin@mail.telepac.pt.

Suresh K. Pandey, MD, is director of SuVi Eye Institute and Research Centre. He can be reached at C 13 Talswandi, Kota, Rajasthan, 324 005, India; email: suvieye@gmail.com.

Mohamad Rosman, MD, is head and senior consultant of refractive surgery at Singapore National Eye Centre. He can be reached at email: mohamad.rosman@singhealth.com.sg.

Disclosures: Budo reports he is a medical monitor and consultant to Ophtec. Marinho reports he is a consultant to Ophtec and Alcon. Pandey and Rosman report no relevant financial disclosures.

 

 

How would you treat a 47-year-old patient with myopia of –7 D and corneal thickness below 500 µm who has become contact lens intolerant and wants to be spectacle independent?

Clear lens exchange with a multifocal lens

In this situation I would do a clear lens exchange with a Symfony (Abbott Medical Optics), a FineVision (PhysIOL) or a Zeiss trifocal IOL. ICL implantation (STAAR) with monovision in one eye can be considered, but these patients typically develop cataract sooner than non-myopes and soon would probably need cataract surgery anyway. Personally, this is also the option I would prefer in a patient who needs to recover distance vision and have spectacle-free reading vision. I would carefully select the type of lens based on the job description, hobbies, driving and reading habits of the patient. I find that in men age 47 to 65 who drive at night or are more the outdoorsy type, the Symfony leads to less glare at night at the cost of not having absolutely perfect near vision. However, if the person does not drive and demands better near vision, I would implant the FineVision or the Zeiss trifocal. I never offer multifocal lens clear lens exchange in patients under 47 years, so this is my cutoff. I do about 300 such cases a year on average and have been offering it as an option since the Acri.Lisa lens (Zeiss) was available in the early 2000s.

Cyres K. Mehta, MS, FASCRS, is an OSN APAO Edition Board Member and chief of surgery, International Eye Centre, Mumbai, India. Disclosure: Mehta reports no relevant financial disclosures.

Monovision with phakic IOLs

I could possibly consider clear lens exchange in a patient with these characteristics if the crystalline lens presented alterations and aberrations. Otherwise, I would rather go for monovision by implantation of phakic IOLs of slightly different powers, setting the dominant eye for distance and the non-dominant eye for near. I would preferably implant an ICL (STAAR), which is a relatively easy office-based procedure to perform under topical anesthesia through a sutureless incision. This lens provides excellent visual quality, is well tolerated and has almost no complications. Should the patient develop cataract at an older age, the ICL can be easily explanted to perform phaco with implantation of a multifocal or trifocal IOL. Another interesting option might be the IPCL, a presbyopic phakic lens produced by Care Group. I have seen several good reports on this lens. STAAR Surgical is currently developing its own presbyopic model, which might be on the market within 6 months to 1 year. These options will definitely expand the use of phakic IOLs to young presbyopes, offering the advantages of a reversible procedure.

Lucio Buratto, MD, is an OSN Europe Edition Board Member and director of Centro Ambrosiano Oftalmico, Milan, Italy. Disclosure: Buratto reports he is a consultant to Abbott Medical Optics, Zeiss, Alcon and Technolas.